WORKSHOP SUMMARY STATEMENT - TERRESTRIAL BIOSPHERIC CARBON FLUXES - QUANTIFICATION OF SINKS AND SOURCES OF CO2

Understanding the role of terrestrial ecosystems in the global carbon (C) cycle has become increasingly important as policymakers consider o ptions to address the issues associated with global change, particular ly climate change. Sound scientific theories are critical in predictin g how these systems may respond in the future, both to climate change and human actions. In March 1993, 60 scientists from 13 nations gather ed in Bad Harzburg, Germany, to develop a state-of-the-science assessm ent of the present and likely future C fluxes associated with the majo r components of the earth's terrestrial biosphere. In the process, par ticular emphasis was placed on the potential for improving C sinks and managing long-term C sequestration. The majority of the week's work w as conducted in eight working groups which independently considered a particular biome or subject area. The working groups considered: the G lobal Carbon Cycle; Boreal Forests and Tundra; Temperate Forests; Trop ical Forests; Grasslands, Savannas and Deserts; Land and Water Interfa ce Zones; Agroecosystems; and Biomass Management. This paper presents a brief overview of their major conclusions and findings. In addition, Table 1 brings together the best estimates from each group as to the current magnitude and estimated future direction of changes in the ter restrial C fluxes.